Discovering thermal relationships in data processing environments

ABSTRACT

A method for discovering thermal relationships in a data processing environment is provided in the illustrative embodiments. An output temperature of a cooling unit operating in the data processing environment is changed from a previous output temperature to a new output temperature. The difference between the previous and the new output temperatures is a change in the output temperature. A change in an ambient temperature proximate to a data processing system is measured. The change in the ambient temperature is a difference between a previous ambient temperature and a new ambient temperature. An expression that represents a relationship between the change in the output temperature and corresponding change in the ambient temperature is determined. The expression is used to determine a cooling correspondence between the cooling unit and the data processing system.

RELATED APPLICATIONS

The present invention is related to similar subject matter of co-pendingand commonly assigned U.S. patent application Ser. No. 12/858,774entitled “THERMAL RELATIONSHIPS BASED WORKLOAD PLANNING,” filed on Aug.18, 2010, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an improved data processingsystem, and in particular, to a computer implemented method foroperating a data processing environment with improved efficiency. Moreparticularly, the present invention relates to a computer implementedmethod for discovering thermal relationships existing between dataprocessing systems and cooling equipment in a data processingenvironment.

2. Description of the Related Art

Data processing environments, such as data centers, often includeseveral data processing systems and facilities equipment. The dataprocessing systems perform or support the computational activities ofthe data processing environment and the facilities equipment maintainthe data processing systems within operating parameters such as bymaintaining desirable temperature, or ensuring adequate power supply.

One type of facilities equipment may be classified as cooling unit orcooling equipment. A cooling unit is any equipment that facilitates thedissipation of heat generated as a byproduct of operating the dataprocessing systems in the data processing environment. An exhaust fan,an air conditioning unit, air ducts, thermostats, and liquid radiatorunits are all examples of cooling equipment.

Often, a data processing environment employs multiple cooling units tomaintain desirable temperatures within the data processing environment.Normally, the data processing environment may also include several dataprocessing systems, which generate the heat that the cooling unitsdissipate. The cooling units are expected to maintain the air in thedata processing environment at a desirable temperature.

SUMMARY OF THE INVENTION

The illustrative embodiments provide a method for discovering thermalrelationships in a data processing environment. An embodiment changes anoutput temperature of a cooling unit operating in the data processingenvironment from a previous output temperature to a new outputtemperature, the difference between the previous and the new outputtemperatures being a change in the output temperature. The embodimentmeasures a change in an ambient temperature proximate to a dataprocessing system, the change in the ambient temperature being adifference between a previous ambient temperature and a new ambienttemperature. The embodiment determines an expression that represents arelationship between the change in the output temperature andcorresponding change in the ambient temperature. The embodiment uses theexpression to determine a cooling correspondence between the coolingunit and the data processing system.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the appended claims. The invention itself; however, as well asa preferred mode of use, further objectives and advantages thereof, willbest be understood by reference to the following detailed description ofan illustrative embodiment when read in conjunction with theaccompanying drawings, wherein:

FIG. 1 depicts a pictorial representation of a network of dataprocessing systems in which the illustrative embodiments may beimplemented;

FIG. 2 depicts a block diagram of a data processing system in which theillustrative embodiments may be implemented;

FIG. 3 depicts a block diagram of an example configuration fordiscovering thermal relationships in a data processing environment inaccordance with an illustrative embodiment;

FIG. 4 depicts a block diagram of an example configuration of a coolingcorrespondence tool in accordance with an illustrative embodiment; and

FIG. 5 depicts a flowchart of a process of discovering thermalrelationship between a cooling unit and a data processing system inaccordance with an illustrative embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention recognizes that new data processing systems may be addedto a data processing environment. The additional heat contributed by thenew data processing systems may have to be dissipated by using thecooling capacity of existing cooling units.

The invention also recognizes that data processing systems are oftenrelocated from one area of the data processing environment to another,such as for reconfiguring a client's rack. The invention recognizes thatwhen a data processing system, a heat source, is physically relocated,the data processing system's dependency on the cooling units may change.For example, the data processing system may be closer to one coolingunit as compared to another cooling unit. Accordingly, the dataprocessing system's heat dissipation may be affected more by one coolingunit versus another.

The invention further recognizes that cooling units may be added orrelocated in a data processing environment. The adding, removing, orrelocating of cooling units may also affect cooling of data processingsystems in the data processing environment in a similar manner.

The invention recognizes that adequate cooling of the data processingsystems operating in a data processing environment is not only importantfrom a facilities management point of view but also from a dataprocessing system performance point of view. It is a well-known factthat performance of data processing systems deteriorate if the ambienttemperature exceeds a certain threshold. Therefore, the inventionrecognizes that determining a relationship between a cooling unit and adata processing system is important for changing either theconfiguration of the data processing systems in the data processingenvironment or the configuration of the cooling units in the dataprocessing environment.

The illustrative embodiments used to describe the invention generallyaddress and solve the above-described problems and other problemsrelated to thermal conditions in data processing environments. Theillustrative embodiments of the invention provide a method fordiscovering thermal relationships in a data processing environment. Anembodiment of the invention may be used for answering the question—whichcooling units contributed to cooling of a data processing system, and towhat extent? An embodiment may also be used for answering theconverse—which data processing system contributes to what proportion ofthe load on a cooling unit?

An embodiment may enable a weighted mapping of the data processingsystems to the cooling units configured in a data processingenvironment. Such weighted mappings represent the thermal relationshipsbetween various data processing systems and various cooling units thatmay be configured in the data processing environment at a given time.

An embodiment may enable predicting effects on data processing systems'performance, cooling units' performance, or both, based on plannedmoves, additions, or changes of equipment. For example, using anembodiment, an administrator may be able to determine whether shuttingdown a cooling unit for maintenance will adversely affect theperformance of a particular data processing system. As another example,an embodiment may enable an administrator to relocate a data processingsystem to utilize available cooling capacity of a certain cooling unitand improve the data processing system's performance without increasingoperating costs.

The illustrative embodiments are described with respect to certain dataonly as examples. Such descriptions are not intended to be limiting onthe invention. For example, an illustrative embodiment described withrespect to adjusting an output air temperature of a cooling unit can beimplemented by adjusting a duty cycle of the cooling unit, in a similarmanner within the scope of the invention.

Furthermore, the illustrative embodiments may be implemented withrespect to any type of data processing system. For example, anembodiment of the invention may be implemented with respect to any typeof client system, server system, platform, or a combination thereof.

The illustrative embodiments are further described with respect tocertain configurations only as examples. Such descriptions are notintended to be limiting on the invention. For example, an illustrativeembodiment described with respect to a heating ventilation and airconditioning (HVAC) type cooling unit can be implemented using rackmounted cooling unit in a similar manner within the scope of theinvention.

An application implementing an embodiment may take the form of dataobjects, code objects, encapsulated instructions, application fragments,drivers, routines, services, systems—including basic I/O system (BIOS),and other types of software implementations available in a dataprocessing environment. For example, Java® Virtual Machine (JVM®), Java®object, an Enterprise Java Bean (EJB®), a servlet, or an applet may bemanifestations of an application with respect to which, within which, orusing which, the invention may be implemented. (Java, JVM, EJB, andother Java related terminologies are registered trademarks of SunMicrosystems, Inc. in the United States and other countries.)

An illustrative embodiment may be implemented in hardware, software, ora combination thereof. The examples in this disclosure are used only forthe clarity of the description and are not limiting on the illustrativeembodiments. Additional or different information, data, operations,actions, tasks, activities, and manipulations will be conceivable fromthis disclosure for similar purpose and the same are contemplated withinthe scope of the illustrative embodiments.

The illustrative embodiments are described using specific code, datastructures, file systems, designs, architectures, layouts, schematics,and tools only as examples and are not limiting on the illustrativeembodiments. Furthermore, the illustrative embodiments are described insome instances using particular data processing environments only as anexample for the clarity of the description. The illustrative embodimentsmay be used in conjunction with other comparable or similarly purposedstructures, systems, applications, or architectures.

Any advantages listed herein are only examples and are not intended tobe limiting on the illustrative embodiments. Additional or differentadvantages may be realized by specific illustrative embodiments.Furthermore, a particular illustrative embodiment may have some, all, ornone of the advantages listed above.

With reference to the figures and in particular with reference to FIGS.1 and 2, these figures are example diagrams of data processingenvironments in which illustrative embodiments may be implemented. FIGS.1 and 2 are only examples and are not intended to assert or imply anylimitation with regard to the environments in which differentembodiments may be implemented. A particular implementation may makemany modifications to the depicted environments based on the followingdescription.

FIG. 1 depicts a pictorial representation of a network of dataprocessing systems in which illustrative embodiments may be implemented.Data processing environment 100 is a network of computers in which theillustrative embodiments may be implemented. Data processing environment100 includes network 102. Network 102 is the medium used to providecommunications links between various devices and computers connectedtogether within data processing environment 100. Network 102 may includeconnections, such as wire, wireless communication links, or fiber opticcables. Server 104 and server 106 couple to network 102 along withstorage unit 108. Software applications may execute on any computer indata processing environment 100.

In addition, clients 110, 112, and 114 couple to network 102. A dataprocessing system, such as server 104 or 106, or client 110, 112, or 114may contain data and may have software applications or software toolsexecuting thereon.

Servers 104 and 106 may include temperature sensing components 105 and107 respectively. Temperature sensing components 105 and 107 may each bea temperature measuring device, a temperature measuring softwareapplication, or a combination thereof, installed in or associated withservers 104 and 106 respectively. Client 112 may include coolingcorrespondence tool 113. Cooling correspondence tool 113 may be anembodiment of the invention implemented as an application for computingthe weighted mapping or correspondence—the thermal relationship—betweena data processing system, such as server 104, and a cooling unit, suchas cooling unit 120. Cooling unit 120 may provide cooling effect 122,which may be a reduction in the ambient air temperature in the vicinityof certain data processing systems in data processing environment 100.For example, cooling effect 122 may cause cooling of servers 104 and106, storage 108, and some networking equipment in network 102.

Servers 104 and 106, storage unit 108, and clients 110, 112, and 114 maycouple to network 102 using wired connections, wireless communicationprotocols, or other suitable data connectivity. Clients 110, 112, and114 may be, for example, personal computers or network computers.

In the depicted example, server 104 may provide data, such as bootfiles, operating system images, and applications to clients 110, 112,and 114. Clients 110, 112, and 114 may be clients to server 104 in thisexample. Clients 110, 112, 114, or some combination thereof, may includetheir own data, boot files, operating system images, and applications.Data processing environment 100 may include additional servers, clients,and other devices that are not shown.

In the depicted example, data processing environment 100 may be theInternet. Network 102 may represent a collection of networks andgateways that use the Transmission Control Protocol/Internet Protocol(TCP/IP) and other protocols to communicate with one another. At theheart of the Internet is a backbone of data communication links betweenmajor nodes or host computers, including thousands of commercial,governmental, educational, and other computer systems that route dataand messages. Of course, data processing environment 100 also may beimplemented as a number of different types of networks, such as forexample, an intranet, a local area network (LAN), or a wide area network(WAN). FIG. 1 is intended as an example, and not as an architecturallimitation for the different illustrative embodiments.

Among other uses, data processing environment 100 may be used forimplementing a client server environment in which the illustrativeembodiments may be implemented. A client server environment enablessoftware applications and data to be distributed across a network suchthat an application functions by using the interactivity between aclient data processing system and a server data processing system. Dataprocessing environment 100 may also employ a service-orientedarchitecture where interoperable software components distributed acrossa network may be packaged together as coherent business applications.

With reference to FIG. 2, this figure depicts a block diagram of a dataprocessing system in which illustrative embodiments may be implemented.Data processing system 200 is an example of a computer, such as server104 or client 110 in FIG. 1, in which computer usable program code orinstructions implementing the processes may be located for theillustrative embodiments.

In the depicted example, data processing system 200 employs a hubarchitecture including North Bridge and memory controller hub (NB/MCH)202 and south bridge and input/output (I/O) controller hub (SB/ICH) 204.Processing unit 206, main memory 208, and graphics processor 210 arecoupled to north bridge and memory controller hub (NB/MCH) 202.Processing unit 206 may contain one or more processors and may beimplemented using one or more heterogeneous processor systems. Graphicsprocessor 210 may be coupled to the NB/MCH through an acceleratedgraphics port (AGP) in certain implementations. In some configurations,processing unit 206 may include NB/MCH 202 or parts thereof.

In the depicted example, local area network (LAN) adapter 212 is coupledto south bridge and I/O controller hub (SB/ICH) 204. Audio adapter 216,keyboard and mouse adapter 220, modem 222, read only memory (ROM) 224,universal serial bus (USB) and other ports 232, and PCI/PCIe devices 234are coupled to south bridge and I/O controller hub 204 through bus 238.Hard disk drive (HDD) 226 and CD-ROM 230 are coupled to south bridge andI/O controller hub 204 through bus 240. PCI/PCIe devices may include,for example, Ethernet adapters, add-in cards, and PC cards for notebookcomputers. PCI uses a card bus controller, while PCIe does not. ROM 224may be, for example, a flash binary input/output system (BIOS). In someconfigurations, ROM 224 may be an Electrically Erasable ProgrammableRead-Only Memory (EEPROM) or any other similarly usable device. Harddisk drive 226 and CD-ROM 230 may use, for example, an integrated driveelectronics (IDE) or serial advanced technology attachment (SATA)interface. A super I/O (SIO) device 236 may be coupled to south bridgeand I/O controller hub (SB/ICH) 204.

An operating system runs on processing unit 206. The operating systemcoordinates and provides control of various components within dataprocessing system 200 in FIG. 2. The operating system may be acommercially available operating system such as AIX® (AIX is a trademarkof International Business Machines Corporation in the United States andother countries), Microsoft® Windows® (Microsoft and Windows aretrademarks of Microsoft Corporation in the United States and othercountries), or Linux® (Linux is a trademark of Linus Torvalds in theUnited States and other countries). An object oriented programmingsystem, such as the Java™ programming system, may run in conjunctionwith the operating system and provides calls to the operating systemfrom Java™ programs or applications executing on data processing system200 (Java is a trademark of Sun Microsystems, Inc., in the United Statesand other countries).

Instructions for the operating system, the object-oriented programmingsystem, and applications or programs are located on storage devices,such as hard disk drive 226, and may be loaded into main memory 208 forexecution by processing unit 206. The processes of the illustrativeembodiments may be performed by processing unit 206 usingcomputer-implemented instructions, which may be located in a memory,such as, for example, main memory 208, read only memory 224, or in oneor more peripheral devices.

The hardware in FIGS. 1-2 may vary depending on the implementation.Other internal hardware or peripheral devices, such as flash memory,equivalent non-volatile memory, or optical disk drives and the like, maybe used in addition to or in place of the hardware depicted in FIGS.1-2. In addition, the processes of the illustrative embodiments may beapplied to a multiprocessor data processing system.

In some illustrative examples, data processing system 200 may be apersonal digital assistant (PDA), which is generally configured withflash memory to provide non-volatile memory for storing operating systemfiles and/or user-generated data. A bus system may comprise one or morebuses, such as a system bus, an I/O bus, and a PCI bus. Of course, thebus system may be implemented using any type of communications fabric orarchitecture that provides for a transfer of data between differentcomponents or devices attached to the fabric or architecture.

A communications unit may include one or more devices used to transmitand receive data, such as a modem or a network adapter. A memory may be,for example, main memory 208 or a cache, such as the cache found innorth bridge and memory controller hub 202. A processing unit mayinclude one or more processors or CPUs.

The depicted examples in FIGS. 1-2 and above-described examples are notmeant to imply architectural limitations. For example, data processingsystem 200 also may be a tablet computer, laptop computer, or telephonedevice in addition to taking the form of a PDA.

With reference to FIG. 3, this figure depicts a block diagram of anexample configuration for discovering thermal relationships in a dataprocessing environment in accordance with an illustrative embodiment.Cooling unit 302 may be similar to cooling unit 120 in FIG. 1. Server304 and temperature sensing component 306 may be similar to server 104and temperature sensing component 105 respectively in FIG. 1.

In accordance with an embodiment, temperature change 308 is effected atcooling unit 302. For example, in one embodiment, temperature change 308may be effected by setting the output temperature setting to a lowerthan previous value. In another embodiment, temperature change 308 maybe effected by altering a baffling position or changing a fan speed. Inanother embodiment, temperature change 308 may be effected by altering aduty cycle of cooling unit 302, by changing the ON and OFF periods ofcooling unit 302. Temperature change 308 may be caused in any mannersuitable for particular cooling unit 302 within the scope of theinvention.

Change in output air temperature 310 of cooling unit 302 occurs as aresult of temperature change 308. For example, a three degrees drop maybe observed as change 310 corresponding to a three degrees temperaturechange 308.

Change in output air temperature 310 may diminish over a distancebetween cooling unit 302 and server 304. Change in input air temperature312 may be the observed change in the temperature of the air flowing inor around server 304.

Temperature sensing component 306 may detect change 312 and outputtemperature change detected 314. For example, for a three degrees dropin temperature change 308, change in input air temperature 312 may onlybe one and one half degrees. Temperature change detected 314 may be themeasured one and one half degrees drop in the input air temperature ascompared to a previously measured input air temperature.

For temperature change detected 314 to be a reliable indicator of thechanged input air temperature, temperature sensing component 306 shouldbe configured to read the input air temperature and produce temperaturechange detected 314 reading after a period has elapsed since temperaturechange 308. Such a period may be configured according to particularimplementation and should be sufficient to allow the air temperature inthe vicinity of server 304 to stabilize after temperature change 308within a predetermined tolerance.

With reference to FIG. 4, this figure depicts a block diagram of anexample configuration of a cooling correspondence tool in accordancewith an illustrative embodiment. Cooling correspondence tool 402 may beimplemented as cooling correspondence tool 113 in FIG. 1.

Temperature change 404 may be the value of temperature change 308 inFIG. 3, forming an input to cooling correspondence tool 402. Temperaturechange detected 406 may be the value of temperature change detected 314in FIG. 4, forming another input to cooling correspondence tool 402.

Using inputs 404 and 406, cooling correspondence tool 402 determinescooling correspondence 408. Cooling correspondence 408 is the thermalrelationship between the cooling unit where temperature change 404 wasapplied and the data processing system where temperature change detected406 was detected.

As a continuation of the previous temperature change example, intemperature change 404 were three degrees, and temperature changedetected 406 were one and one half degrees, cooling correspondence maybe a ratio of temperature change detected 406 and temperature change404. Accordingly, for this example, cooling correspondence may be 0.5(1.5 divided by 3). In other words, a data processing system wheretemperature change detected 406 is detected experiences only fiftypercent of the change in cooling caused by the cooling unit wheretemperature change 404 is made.

A ratio of input 404 and 406 as cooling correspondence 408 is describedonly as an example and is not intended to be limiting on the invention.For example, additional inputs may be provided to cooling correspondencetool 402. For example, through trial and error or another method, it maybe known smaller than a threshold temperature change 404 results intemperature change detected 406 according to one proportion, but alarger than a threshold temperature change 404 results in a differentproportional temperature change detected 406.

For example, if temperature change 404 is three degrees, temperaturechange detected is one and one half degrees, but if temperature changeis ten degrees, temperature change detected may be seven degrees.Ambient factors, atmospheric factors, other cooling units' duty cyclesand settings, condition of equipment such as a filtering device, andmany other factors may cause such variance in the proportion betweentemperature change 404 and temperature change detected 406.

Accordingly, additional inputs, such as a constant or coefficient valueto use in the computation of cooling correspondence 408 are contemplatedfor cooling correspondence tool 402. One method of determining anaccurate cooling correspondence between a cooling unit and a dataprocessing system may benefit from minimizing or eliminating otherfactors that may affect temperature change detected 406. Temperaturechange 404 may be assigned different values and correspondingtemperature change detected value 406 may be noted while the otherfactors are minimized or eliminated. A curve may be plotted with thecorresponding values of temperature change 404 and temperature changedetected 406. A mathematical expression for representing the curve maybe determined by using any known methods. The mathematical expressionmay then be used for determining cooling correspondence 408.

Additional inputs may also be provided to cooling correspondence tool402 according to the mathematical expression. For example, when a singlecooling unit cannot be operated with other cooling units minimized oreliminated, the mathematical expression may require output temperaturesof the other operating cooling units to output an accurate value forcooling correspondence 408. Such output temperatures of the othercooling units may serve as additional inputs to cooling correspondencetool 402.

With reference to FIG. 5, this figure depicts a flowchart of a processof discovering thermal relationship between a cooling unit and a dataprocessing system in accordance with an illustrative embodiment. Process500 may be implemented in cooling correspondence tool 402 in FIG. 4.

Process 500 begins by changing the output air temperature of a coolingunit (step 502). Process 500 allows the ambient temperature to stabilizeafter the change (step 504). Process 500 measures a change in the inputair temperature, or the vicinity air temperature, of a data processingsystem (step 506). The change in step 506 is in comparison to an inputair temperature before the change in step 502 was made.

Process 500 may repeat steps 502-506 any number of times, and record thevalues of changes in step 502 and 506 for each change. Using therecorded values, process 500 computes an expression that represents therelationship between the change in the input/vicinity air temperature atthe data processing system and the change in the cooling unit'stemperature (step 508).

Process 500 may output the value of the expression as the coolingcorrespondence between the cooling unit and the data processing system(step 510). Process 500 ends thereafter. An embodiment may produce thecooling correspondence value at a certain output air temperature of thecooling unit.

The components in the block diagrams and the steps in the flowchartsdescribed above are described only as examples. The components and thesteps have been selected for the clarity of the description and are notlimiting on the illustrative embodiments of the invention. For example,a particular implementation may combine, omit, further subdivide,modify, augment, reduce, or implement alternatively, any of thecomponents or steps without departing from the scope of the illustrativeembodiments. Furthermore, the steps of the processes described above maybe performed in a different order within the scope of the invention.

Thus, a computer implemented method is provided in the illustrativeembodiments for discovering thermal relationships in a data processingenvironment. Using an embodiment of the invention, thermal relationshipsbetween heat sources—the data processing systems—and cooling units canbe created. Such thermal relationships provide information about how thecooling capacity of each cooling unit separately, and of the coolingequipment of a data processing environment as a whole, is beingutilized. Thermal relationships discovered by an embodiment can be usedto, for example, improve cooling capacity utilization, predict coolingcapacity overload, predict data processing system underperformance, andconfigure data processing systems to use the available cooling capacityoptimally for the workload that is to be executed.

The invention can take the form of an entirely software embodiment, oran embodiment containing both hardware and software elements. In apreferred embodiment, the invention is implemented in software orprogram code, which includes but is not limited to firmware, residentsoftware, and microcode.

As will be appreciated by one skilled in the art, aspects of the presentinvention may be embodied as a system, method, or computer programproduct. Accordingly, aspects of the present invention may take the formof an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, microcode, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present invention may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Morespecific examples (a non-exhaustive list) of the computer readablestorage medium would include the following: an electrical connectionhaving one or more wires, a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,a portable compact disc read-only memory (CD-ROM), an optical storagedevice, a magnetic storage device, or any suitable combination of theforegoing. In the context of this document, a computer readable storagemedium may be any tangible medium that can contain, or store a programfor use by or in connection with an instruction execution system,apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electromagnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, etc., or any suitable combination ofthe foregoing.

Further, a computer storage medium may contain or store acomputer-readable program code such that when the computer-readableprogram code is executed on a computer, the execution of thiscomputer-readable program code causes the computer to transmit anothercomputer-readable program code over a communications link. Thiscommunications link may use a medium that is, for example withoutlimitation, physical or wireless.

A data processing system suitable for storing and/or executing programcode will include at least one processor coupled directly or indirectlyto memory elements through a system bus. The memory elements can includelocal memory employed during actual execution of the program code, bulkstorage media, and cache memories, which provide temporary storage of atleast some program code in order to reduce the number of times code mustbe retrieved from bulk storage media during execution.

A data processing system may act as a server data processing system or aclient data processing system. Server and client data processing systemsmay include data storage media that are computer usable, such as beingcomputer readable. A data storage medium associated with a server dataprocessing system may contain computer usable code. A client dataprocessing system may download that computer usable code, such as forstoring on a data storage medium associated with the client dataprocessing system, or for using in the client data processing system.The server data processing system may similarly upload computer usablecode from the client data processing system. The computer usable coderesulting from a computer usable program product embodiment of theillustrative embodiments may be uploaded or downloaded using server andclient data processing systems in this manner.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the system eitherdirectly or through intervening I/O controllers.

Network adapters may also be coupled to the system to enable the dataprocessing system to become coupled to other data processing systems orremote printers or storage devices through intervening private or publicnetworks. Modems, cable modem and Ethernet cards are just a few of thecurrently available types of network adapters.

The description of the present invention has been presented for purposesof illustration and description, and is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the art. Theembodiment was chosen and described in order to explain the principlesof the invention, the practical application, and to enable others ofordinary skill in the art to understand the invention for variousembodiments with various modifications as are suited to the particularuse contemplated.

What is claimed is:
 1. A computer implemented method for discoveringthermal relationships in a data processing environment, the computerimplemented method comprising: changing an output temperature of acooling unit operating in the data processing environment from aprevious output temperature to a new output temperature, wherein thedifference between the previous and the new output temperatures is achange in the output temperature, wherein the cooling unit is separatefrom and provides cooling to a plurality of data processing systems inthe data processing environment; measuring a change in an ambienttemperature proximate to a data processing system, the plurality of dataprocessing systems including the data processing system, wherein thechange in the ambient temperature is a difference between a previousambient temperature and a new ambient temperature; determining, using aprocessor and a memory, an expression that represents a relationshipbetween the change in the output temperature and corresponding change inthe ambient temperature; evaluating the expression, using the processorand the memory, to determine a cooling correspondence between thecooling unit and the data processing system; computing, using therelationship, a fraction of cooling contributed by the cooling unit tothe data processing system and a fraction of thermal load contributed bythe data processing system from the plurality of data processing systemsto the cooling unit; and utilizing the computed fraction of the coolingand the computed fraction of the thermal load to modify a configurationof the data processing system for a workload.
 2. The computerimplemented method of claim 1, further comprising: repeating thechanging and the measuring to generate plurality of values of change inthe output temperature and corresponding change in the ambienttemperature, where the plurality of values are used in determining theexpression.
 3. The computer implemented method of claim 1, wherein thecooling correspondence is determined from evaluating the expression at agiven output temperature of the cooling unit.
 4. The computerimplemented method of claim 1, further comprising: allowing the ambienttemperature to stabilize at a new temperature resulting from thechanging.
 5. The computer implemented method of claim 1, wherein the newambient temperature fluctuates within a tolerance value.
 6. The computerimplemented method of claim 1, wherein the ambient temperature is aninput air temperature of the data processing system, as determined by atemperature sensing component of the data processing system.